At first, only a few things are known about the celestial object that astronomers dub Rama. When a space probe confirms that it is an interstellar spacecraft, explorers and scientists prepare for mankind's first encounter with alien intelligence. "An enormous cylindrical object has entered Earth’s solar system on a collision course with the sun. A team of astronauts are sent to explore the mysterious craft, which the denizens of the solar system...

By the twenty-third century Earth has already had two encounters with massive, mysterious robotic spacecraft from beyond our solar system--the incontestable proof of an alien technology that far exceeds our own. Now three human cosmonauts are trapped aboard a labyrinthine Raman vessel, where it will take all of their physical and mental resources to survive.